It is desirable to measure and analyze a vehicle's weight transfer and compliance characteristics during certain inertial events in order to gain a better understanding of the vehicle's resistance to rollover and structural compliance attributes. For example and without limitation, understanding a vehicle's resistance to rollover during various inertial events allows the safety devices within a vehicle (e.g., seat belt pretensioners, airbags) to be deployed in a timely and proper fashion to protect the occupants of the vehicle in situations where a rollover may be imminent. Furthermore, this information can be used to modify the vehicle to increase its resistance to rollover in certain situations and/or to meet certain structural compliance requirements or desires.
Efforts have been made to determine and/or analyze a vehicle's resistance to rollover in certain situations and to measure the vehicle's compliance attributes in those situations. Prior efforts include disposing various sensors on a vehicle and causing the vehicle to perform various maneuvers on a test track or in other testing environments. Readings are taken from the sensors which provide information regarding the various forces on the vehicle, the vehicle's speed, turning radius, and other vehicle attributes. This information can then be used to analyze the vehicle's resistance to rollover (e.g., by examining the data received just prior to the vehicle tipping or "rolling over") and/or compliance attributes (e.g., by examining the displacement, stress, strain or bending experienced by portions of the vehicle). While these prior methods provide information relevant to a vehicle's rollover resistance and structural compliance characteristics, they suffer from some drawbacks.
For example and without limitation, because the sensor readings are taken in real time during testing maneuvers, it is difficult, if not impossible, to determine all of the forces acting on the vehicle and/or the vehicle's structural compliance attributes at any one instance in time and/or at a particular inertial state. Particularly, an excessive amount of sensors would have to be deployed on the vehicle and simultaneously monitored. Such an excessive amount of sensors would be difficult to accurately and simultaneously monitor and could, themselves, alter the performance of the vehicle. Hence, prior methods typically use fewer sensors which do not provide sufficient information to fully quantify a vehicle's rollover resistance and structural compliance attributes during certain inertial events.
Applicant's invention addresses these drawbacks and provides a new and improved method and an apparatus for measuring the rollover resistance and dynamic compliance characteristics of a vehicle.